Lost motion cartridge for keys in knob locks



Nov. 3, 1953 I H. YOUNG LOST MOTION CARTRIDGE FOR KEYS IN KNOB LOCKS Filed on. 23, 1951 2 Sheets-Sinai 1 IN VENTOR Herbert Young ATTORNEY I NOV. 3, H. YOUNG LOST MOTION CARTRIDGE FOR KEYS IN KNOB LOCKS Filed Oct. 23, 1951 2 Sheets-Sheet 2 INVENTOR erbert Young ATTORNEY position,

Patented Nov. 3, 1953 LOST MOTION CARTRIDGE FOR KEYS IN KNOB LOCKS Herbert Young, Grand Rapids, Mich., assignor to National Brass Company, Grand Rapids, Mich., a corporation of Michigan Application October 23, 1951, Serial No. 252,618

11 Claims.

This invention relates to lock structures and more particularly to a compact, self contained, lost motion assembly designed to be seated within the shank of the outside knob of a key-in-knob type lock. The interior mechanism of the keyin-knob lock consists of a number of small parts which heretofore had to be individually assembled in the final operation of constructing such a structure at the factory. These numerous parts make the assembly process both long and expensive. It is, therefore, a very desirable object in designing this type of lock to eliminate as many parts as possible and to design the lock so that its interior mechanism may be broken down into as many complete sub-assemblies as possible. By the use of sub-assemblies, it is possible to greatly reduce the total assembly time since each person making an assembly only has to work with a small number of related parts. The final assembly then consists of the arrangement and securing together of a small number of compact sub-assemblies. This invention accomplishes this by making the lost motion mechanism, mounted within the shank of the outside knob, a complete and self contained sub-assembly. In addition, this invention materially reduces the number of parts forming this subassembly.

Another important aspect in the design of the internal mechanism for these key-in-knob locks :is the creation of a structure operating with maximum ease. Ease in operation materially improves the life of the mechanism. The aver- :age door lock is subjected to many operating cycles a day and must sustain these operations for many years. The mechanisms operation must be such that it performs its function easily and in a simple manner whereby the operator will become neither confused or irritated by a complex operating cycle. This invention accomplishes these purposes by providing a mechanism which is positive at every operation and simple to use. These and other objects and purposes of my invention will be immediately seen by those acquainted with the design and fabrication of lock structures upon reading the following specification and the accompanying drawings.

In the drawings:

Figure 1 is a central, sectional view of a keyin-knob lock incorporating the improved lost motion assembly, showing the outside knob in released position.

Figure 2 is a central, sectional view of an outside knob equipped with the improved lost motion assembly sh ng e outside knob locked 2 Figure 3 is an exploded view of the outside knob assembly.

Figure 4 is an exploded view of the improved lost motion assembly.

Figure 5 is an enlarged, partially fragmentary view of the shell for the improved lost motion assembly.

Figure 6 is a sectional view taken along the plane VI-VI of Figure 5.

Figure 7 is an enlarged, fragmentary view of the shell for the improved lost motion assembly showing the shell rotated 90 with respect to Figure 5.

Figure 8 is a fragmentary view of the inner end of the knob shank within which the improved lost motion assembly is mounted.

'motion assembly.

Figure 11 is a sectional View taken along the plane XI-XI of Figure 10.

Figure 12 is an elevation view of the snap ring used for mountin the improved lost motion assembly. 7

In executing the objects and purposes of my invention, I have provided a tubular shell designed to be seated within the hollow shank of an outside knob. The shell at its outward end has a pair of ears for engaging the lock barrel mounted at the center of the outside knob. At its inner end the shell is provided with a noncircular shaft for engaging one roll-back of a latch assembly. Within the shell there is mounted a barrier member designed, in one position, to operatively connect the knob shank with the shell and in another position to disconnect the knob shank from the shell and to lock the knob shank against rotation. The barrier member is provided with means to move it from locked to unlocked position. In the locking position, the barrier member permits free rotation of the shell under the influence of the lock barrel. The entire lost motion assembly is enclosed within the shell.

In the following description the terms inwardly and outwardly" are frequently used and are to be taken to mean inwardly in the direction of the inside knob or toward the bottom of Figure 1 and outwardly away therefrom. The terms inside and "outside are to be considered as having the same meaning as inwardly and outwardly.

Referring to the drawings in detail, the nu- -meral I indicates a door having a latch opening inner end 4 normally square shaft 42. centric to the shell 46 and has a central opening 2 and a transverse spindle opening 3. Mounted within the latch opening 2 is a latch assembly i having a bolt 5 operated by means of a pair of independent rollbacks 6 and 6a. On the inside of the door, there is mounted an inside knob assembly 1 axially aligned with the outside knob assembly ii mounted on the outside of the door.

The inside knob assembly 1 consists of a knob shell Ill having a tubular shank The shank II is rotatably received in the collar portion 25 of the escutcheon plate l2. The knob shell [8 has a central opening l3 communicating with the interior of the tubular shank Seated within the central opening |3 is a cup-shaped button l4 having an exterior finger grip I5. A cup-shaped cap i6 is received into the other or outer end of the shank H. The cap member I6 is secured to the shank I! for rotation therewith by the key l1 and is held against axial disengagement from the shank II by the snap ring l8. A disc l9 having a rectilinear, central opening is secured to the inner end of the button l4 for movement with the button. A push rod 28 of non-circular cross-section extends through the opening in the disc it, through the roll-backs 6 and 6a and into the outside knob assembly 8. The inner end of the rod 20 bears against the inside end wall of the button M. The rod 20 is gripped by the disc IQ for rotation with the button A spring 2! seated within the shank H and cap l6 urges the button l4 inwardly against a shoulder stop 22.

The cap i6, at its inner end, is provided with a central, non-circular opening for receiving the non-circular stud 23 of the roll-back 6. By means of this connection rotary motion of the knob l transmitted to the cap l6 by the key |1 rotates the roll-back 6 for reciprocating the bolt The outside knob assembly consists of a hollow knob shell 3|! having a central opening through its outer face for receiving the lock barrel 3|. The knob shell 36, through its inner end, receives a tubular shank 32. The shank 32 is secured to the knob shell 38 by means of screws 33. The shank 32 rotatably seats within the collar portion 34 of the outside escutcheon plate 35. The inside knob assembly 1 and the outside knob assembly 8 are held together and simultaneously clamped to the door I by the screws 36 engaging the internally threaded pillars 31.

The above described structure constitutes the structural assembly within which my invention operates and with which it cooperates. This structure is neither described nor illustrated in detail, beyond that necessary for a complete understanding of the invention. 7

The above structure is disclosed in the copending applications Serial No. 47,437, filed September 2, 1948, inventor: Herbert Quigley, now Patent No. 2,632,664, and Serial No. 47,438, filed September 2, 1948, inventor: Herbert Quigley.

The subject of this invention is the assembly for connecting both the lock barrel 3| and the shank 32 to the roll-back 6a. This assembly consists oi a housing or shell 40 having a closed Secured to the end 4| and extending outwardly therefrom is a non-circular,

The shaft 42 is con- 39 (Figure 6) for receiving the push rod 28 therethrough without operative engagement between the shaft and the rod. The inner end of the shaft 42 engages the roll-back 6a and transmits -.rotary motion from the shell 40. to the roll-back.

The outer end of the shell 48 has a pair of longitudinally extending, diametrically spaced ears 43 (Figures 2 and 5) adapted to be received into mating openings in the lock barrel 3|. The ears 43 transmit rotary motion from the lock barrel 3| to the shell 40.

The push rod 20 extends into the shell 48 and, at its outer end within the shell, has a pair of outwardly extending ears 44 forming a bar or T-shaped head 45. The outer end of the head 45 has a shallow notch 46 of substantial length, centered about the center line of the rod 26. Outwardly of the head of the rod 20 is a somewhat T-shaped barrier member 41. The barrier member 41 has a pair of projecting wings 48 on its inner end. The inner face of the barrier member 41, between the wings 48, has a shallow notch 49 (Figure 4) similar to the notch 46 in the head 45 of the rod 20. The notch 49 is centered about the center line of the barrier member 41. outwardly of the wings 48 the barrier member has a pair of shoulders 50 for seating the spring 5|. The outer end of the housing 40 is closed by a substantially circular plate 52. The other end of the spring 5| bears against the plate 52.

The shell 48 is provided with a pair of diametrically positioned, L-shaped openings (Figure 1). Each of the openings 66 consists of a narrow slot or leg 6| extending axially of the shell and a broad, circumferentially extending opening 62 communicating with the outward end of the slot 6|. The width of the slot 6| is only slightly greater than the thickness of the wings 48 of the barrier member 41. The slot 6| extends inwardly a sufficient distance to firmly seat the wings 48 of the barrier member 41 and hold the barrier member against rotation with respect to the shell 40.

The inward portion of the shank 32 is provided wtih a slot 64 (Figure 8) similar to the slot 6| but preferably extending inwardly slightly further than the slot 6| and extending outwardly slightly further than the outward wall of the opening 68. The additional length of the slot 64 is only to eliminate possible difiiculty arising from manufacturing tolerances causing the slot 64 to be shorter than the slot 6| thereby causing interference with the proper operation of the barrier member 41.

The outside escutcheon plate 35 has an annular channel 65 (Figures 1, 2 and 9) extending around the inner end of the central opening through the escutcheon plate. The channel 65 communicates with the central opening in the escutcheon plate and is of sufi'icient depth to seat the wings 48 of the barrier member 41. A pair of diametrically positioned notches 66 extend outwardly from the annular channel 65. The notches are of sufilcient depth to permit free movement of the wings 48, as the wings move axially of the shell 40. The purpose of the channel 65 and notches 66 will be explained more fully under Operation.

The shell 40, adjacent its closed end 4|, has a shoulder element or support member 16 seated within it (Figures 4, 5 and 6). The support member 10 is curved to seat snugly against the inside Wall of the shell 40 and includes an inclined surface 1|,a seat 12 and a stop shoulder 13. The stop shoulder 13 and the seat 12 are separated by a notch 14. It will be recognized that the seat 12 can be eliminated, bringing the inclined surface 6| directly up to the notch 14. The support member 18 seats against the closed end of the shell 40 and is secured to the-shell wall by any suitable means such as welding. The support member 10 is so located within the shell 48 that the stop shoulder 13 does not project into the circumferential opening 62 of one of the openings 60. Further, it is so located that the shell 48 may be rotated the length of the opening 62 in the shell 40 without interference between the barrier member 41 and the head 45 when the head is seated in the notch 74. The size and purpose of the support member 10 will be described more fully under Assembly and Operation.

The shell 40 is held within the shank 32 by the retaining washer 80 and the snap ring 8| (Figures 1, 2, 10, 11 and 12). The retaining washer 80 has a shallow, central cup along the sides of which are a pair of elongated, diametrically positioned slots 82. The retaining washer 80 is designed to seat over the end of the shank 32 with each of the projections 83 on the shank 32 passing through one of the openings. The washer 88 has a central opening for passage of the shaft 42. The snap ring 8| is split at 84. An inwardly pro- J'ecting tooth 85 is provided on each side of the split 84 together with a diametrically positioned tooth 86. The teeth 85 and 86 are designed to seat into the radial slots 81 in the projections 83 on the shank 32.

Assembly and operation My key-in-knob type lock is designed to provide a latch bolt which may be independently operated by either knob. In addition, by pressing the button in the inner knob outwardly and rotating it, operation of the outside knob may be prevented by locking the shank of the outside knob to the outside escutcheon plate. The structure is so designed that while the outside knob i locked, the latch bolt may be retracted by means of a key inserted into the lock barrel in the outside lock. Operation of the latch bolt by means of the key will not afiect release of the outside knob nor will it necessitate rotation of the inside knob or any of the structure related to the inside knob. The outside knob may only be released by rotating the button in the inside knob and permitting it to move inwardly under the urging of the spring supporting the button. This invention relates to the particular structure by which the outside knob is locked or released and the latch bolt operated by means of a key while the outside knob is locked.

In assembling my invention, the outside knob shell 30, lock barrel 3| and shank 32 are each assembled. The outside escutcheon plate 35 is then seated around the shank 32. The outside knob assembly is now ready to receive the structure constituting my invention as a complete subassembly.

The shaft 42 is mounted to the shell 40. The closed end 4| of the shell may be integral with the side walls of the shell 48 or a part previously assembled to the shell by means of welding or suitable fasteners. The rod 20 with its head 45 is then passed through the shell with the rod passing through the shaft 42. The barrier member 41 is put in place and the spring seated upon the barrier member. The circular plate 52 is secured into place by welding or other suitable fastening means to retain the spring.

With the installation of the circular plate, the assembly of the lost motion cartridge is complete. This cartridge is then passed outwardly into the outside knob assembly with the ears 43 engaging mating channels in the lock barrel 3|. A spacer washer 88 of the correct thickness is seated around the inward end of the cartridge together with the retaining washer. 80. The snap ring is put in place by spreading. the teeth 85, seating the tooth 86 in one of the slots 81 in the shank 32 and then seatin each of the teeth 85 in the other slot 81. In this position, the snap ring locks the retaining washer 88 against the end of the cartridge and against the washer 88. The thickness of the washer 88 will vary from one assembly to another since it is used to overcome differences occurring because of the accumulation of small manufacturing tolerances. Therefore, a number of washers 88 of different thicknesses must be provided. The outside knob, as so assembled, is mounted on a door by passing the rod 20 through the rollbacks 6 and 8a of the latch assembly 4. The inside knob is then put in place by seating it over the end of the rod 20 and installing the screws 36. The escutcheon plates l2 and 35 are, by the screws 38, rendered stationary upon the door.

With the structure in the position appearing in Figure l, the barrier member 41 is in its inward position and as such the wings 48 are seated in the channel 65. In this position, the latch bolt 5 may be retracted by rotation of either the inside or outside knob. Operation of one will not cause rotation of the other because there is no rotary, operative connection between the inside and outside knobs and the roll-backs 6 and 6a are designed for independent and separate operation. The outside knob is free to rotate since the wings 48 of the barrier member are now seated in the slot or axial leg SI of the openings 68 of the shell 40, in the inward end of the slot 64 in the knob shank 32 and in the channel 65. Thus, upon rotation of the knob shell 30, the shank 32 will rotate and this motion will be transmitted by the wings 48 to the shell 40. Since the shell 40 is connected to the shaft 42, this rotary motion will be transmitted to the rollback Go for retraction or extension of the latch bolt 5.

When it is desired to lock the outside knob against rotation, the push button [4 is pressed outwardly, that is, into the inside knob, and, by means of the grip I5, rotated. The outward movement of the push button and the rod 20 moves the barrier member axially of the shell 48 pushing it into the notches 65, out of the slot 6| in the shell 40 and into alignment with the circumferential leg 62 of the opening 60. In this position, the shell 40 is free to rotate without interference from the barrier member through an are representing the length of the opening 82. The barrier member, however, is held against rotation by the notches 68. Since it remains seated in the slot 64 in the knob shank, the knob shank is also held against rotation. As the rod 20 is forced outwardly and is rotated, one of the ears '44 of the head 45 will pass outwardly of the inclined surface H and the seat 12 of the support member 10. Continued rotation of the head 45 will bring it into contact with the stop shoulder 13. Upon release of the push button l4 the ear 44 will be forced into the notch 14 by the spring 5|. When seated in the notch 14, the head 45 is held outwardly a substantial distance from the closed end 4| of the shell 40. In this position,

the wings 48 of the barrier member are not only released from the slot 6| in the shell 40 but are substantially spaced from the inner wall 90 and opening 80. Thus, not only is the head 45 held against accidental, inward movement or rotation with respect to the shell 40 but the barrier member is held in such a position that it offers no resistance to the rotation of the shell 46 even though the barrier member is stationary. This assures ease of operation as well as contributing materially to the lift of the mechanism. Since there is no drag or other pull on the wings 48 there is no danger of these wings becoming bent or worn due to engagement between these wings and the inward wall 90 of the opening 60. By the use of the support member Hi, the operation of the push button 14 is made positive. It is positively held in its inward position and the proper point at which it should be released to securely lock the outside knob is automatically registered when the head 45 contacts the stop shoulder 13. Further, a positive operation in the form of pushing the button [4 outwardly and then rotating it is necessary to release the outside knob.

With the'barrier member 41 in its outward position, the latch bolt 5 may be retracted by means of a key inserted in the lock barrel 3 l. The shell 40 is directly connected to the lock barrel 3! and the circumferential leg 62 of the opening 6i! permits the shell 40 to be rotated with respect to the barrier member 41. The shell 40 is directly connected to the roll-back Go for operation of the latch structure. The use of the interengaging notches 46 and 49 in the head 45 and the barrier member 41 respectively maintain the head and barrier member properly aligned and in constant engagement with a minimum of contacting area or surface to cause frictional resistance. Since the engagement of these two members is at and closely about the center of rotation, the drag imposed by the contact between these two parts will be negligible. It is important that the drag imposed by relative rotation between the head 45 and the barrier member 41 be kept at a minimum because there is always contact between these parts due to the influence of the spring 5|. since the head 45 is held in the notch 14, when in its inward position, it must rotate with the shell 40 while the barrier member 41 is held stationary by the notches 66.

Due to the influence of springs used in the latch assembly 4, the roll-backs 6 and to always come to rest at the same point in their rotation. This occurs whenever the knobs are released after a full or partial operating cycle. The roll-backs always rotate the shell 49 to the same reference point. Since the barrier member always con nects the shell 40 and the shank 32 when the outside knob is operatively connected to the latch assembly, the shank 32 is always returned by the shell 40 to this same reference point. Thus, the Wings 48 of the barrier member 2'! will always be aligned with the notches 66 when the outside knob is at rest.

I have described a preferred embodiment of my invention. Modifications of my invention may be made without departing from the principle there- Each of these modifications is to be considered as included in the hereinafter appended .claims unless these claims specifically provide otherwise. I claim: 1. In a lost motion assembly adapted to be received in the knob shank of theoutside knob of a key-in-knob-lock, the combination comprising: a tubular shell closed on one of its ends; a hollow shaft mounted to said closed end of said shell concentrically thereof and projecting away from said shell; an aperture through the closed end of said shell aligned with said shaft; a bar rotatably seated within said shell; 2. rod on said bar extending through said aperture and said shaft; the walls of said shell defining an L-shaped opening having one leg arranged longitudinally of said shell and the other leg circumferentially of said shell; said other leg being spaced from said closed end of said shell; a barrier member within said shell, said barrier member being rotatable with respect to said bar; said barrier member having a wing adapted to pass through said L-shaped opening; a resilient element within said shell bearing against said barrier member and urging said barrier member against said bar and said bar against said closed end of said shell; a support in said shell adjacent the closed end of said shell, said support adapted to hold said bar, when said bar is rotated into alignment therewith, spaced from the closed end of said shell; said wing on said barrier member, when said bar is seated upon said support, being aligned with said other leg of said opening and spaced from the circumferentially extending walls thereof.

2. In a lost motion assembly adapted to be received in the knob shank of the outside knob of a key-in-knob lock, the combination comprising: a tubular shell closed on one of its ends; a hollow shaft mounted to said closed end of said shell concentrically thereof and projecting away from said shell; an aperture through the closed end of said shell aligned with said shaft; a bar rotatably seated within said shell; a rod on said bar extending through said aperture and said shaft; the walls of said shell defining an L-shaped opening having one leg arranged longitudinally of said shell and the other leg cir cumferentially of said shell; said other leg being spaced from said closed end of said shell; a barrier member within said shell, said barrier member being rotatable with respect to said bar; said barrier member having a wing adapted to pass through said L-shaped opening; a resilient element within said shell bearing against said barrier member and urging said barrier member against said bar and said bar against said closed end of said shell; a notched support in said shell adjacent the closed end of said shell, said support adapted to hold said bar, when said bar is seated in said notch, spaced from the closed end of said shell; said wing on said barrier member, when said bar is seated in said notch, being aligned with said other leg of said openings and spaced from .the circumferentially extending Walls thereof.

3. In a lost motion assembly adapted to be received in the knob shank of the outside knob of a key-in-knob lock, the combination comprising: a tubular shell closed on one of its ends and open on the other of its ends; a hollow shaft mounted to said closed end of said shell concentrically thereof and projecting away from said shell; an aperture through the closed end of said shell aligned with said shaft; a bar rotatably seated within said shell; a rod on said bar extending through said aperture and said shaft; the walls of said shell defining an L-shaped opening having one leg arranged longitudinally of said shell and the other leg circumferentially of said shell; said other leg being spaced from said closed end of said shell; a barrier member within said shell, said barrier member being rotatable with respect to said bar; said barrier .member having a wing adapted to pass through said L-shaped opening; closure means for the 9, open end ,ofsaid shell; a resilient element within "said shell bearing against said closure means and said barrier member and urging said barrier .member against said bar and said bar against said closed end of said shell; a support in said shell adjacent the closed end of said shell, said support adapted to hold said bar, when said bar is rotated into alignment therewith, spaced from the closed end of said shell; said wing on said barrier member, when said bar is seated upon said support, being aligned with said other leg of said opening and spaced from the circumferentially extending walls thereof.

4. In a lost motion. assembly adapted to be received in the knob shank of the outside knob of a key-in-knob lock, the combination comprising: a tubular shell closed on one of its ends; an aperture through the closed end of said shell, said aperture being concentric with said shell; a bar rotatably seated within said shell; a rod on said bar extending through said aperture; the walls of said shell defining an L-shaped opening having one leg arranged longitudinally of said shell and the other leg circumferentially of said shell; said other leg being spaced from said closed end of said shell; a barrier member within said shell, said barrier member being rotatable with respect to said bar; said barrier member having a Wing adapted to pass through said L-shaped opening; a resilient element within said shell bearing against said barrier member and urging said barrier member against said bar and said bar against said closed end of said shell; a support in said shell adjacent the closed end of said shell, said support adapted to hold said bar, when said bar is rotated into alignment therewith, spaced from the closed end of said shell; said wing on said barrier member, when said bar is seated upon said support, being aligned with said other leg of said opening and spaced from the circumferentially extending walls thereof.

5. In a lost motion assembly adapted to be received in the knob shank of the outside knob of a key-in-knob lock, the combination comprising: a tubular shell closed on one of its ends; a hollow shaft mounted to said closed end of said shell concentrically thereof and projecting away from said shell; an aperture through the closed end of said shell aligned with said shaft; a bar rotatably seated within said shell; a rod on said bar extending through said aperture and said shaft; the walls of said shell defining a pair of diametrically spaced L-shaped openings each having one le arranged longitudinally of said shell and the other leg circumferentially of said shell; said other legs being spaced from said closed end of said shell; a barrier member within said shell, said barrier member being rotatable with respect to said bar; said barrier member having a pair of wings, each of said wings adapted to pass through one of said L-shaped openings; a resilient element within said shell bearing against said barrier member and urging said barrier member against said bar and said bar against said closed end of said shell; a support in said shell adjacent the closed end of said shell, said support adapted to hold said bar, when said bar is rotated into alignment therewith, spaced from the closed end of said shell; said wings on said barrier member, when said bar is seated upon said support, being aligned with the other leg of said openings and spaced from the circumferentially extendin walls thereof.

6. In a lost motion assembly adapted to be received in the knob shank of the outside knob of a key-in-knob lock, the combination comprising: a tubular shell closed on one of its ends; a bar rotatably seated within said shell; means for moving said bar longitudinally of said shell; the walls of said shell defining an L-shaped opening having one leg arranged longitudinally of said shell and the other leg circumferentially of said shell; said other leg being spaced from said closed end of said shell; a barrier member within said shell, said barrier member being rotatable with respect to said bar; said barrier member having a wing adapted to pass through said L- shaped opening; a resilient element within said shell bearing against said barrier member and urging said barrier member against said bar and said bar against said closed end of said shell; a support in said shell adjacent the closed of a key-in-knob lock, the combination comprising: a tubular shell closed on each of its ends; a concentric aperture through one of said ends of said shell; a bar rotatably seating within said shell; a rod on said bar extending through said aperture; the walls of said shell defining an 'L-shaped opening having one leg arranged longitudinally of said shell and the other leg circumferentially of said shell; a barrier member within said shell and rotatable with respect to said bar; said barrier member having a wing adapted to pass through said L-shaped opening; a resilient element within said shell bearing against said barrier member and urging said barrier member against said bar and said bar against said one end of said shell; a notched support in said shell; said support adapted to hold said bar, when said bar is seated in said notch, spaced from said one end of said shell; said wing on said barrier member, when said bar is seated in said notch, being aligned with said other leg of said opening and spaced from the circumferentially extending Walls thereof.

8. In a lost motion assembly for a key-in-knob lock having a knob and tubular knob shank, a lock barrel rotatably mounted in said knob, a latch and a roll-back for operating said latch, said lost motion assembly adapted to connect both said shank and said lock barrel to said rollback, the combination comprising: a hollow shell rotatably received into said shank; means at one of the ends of said shell for connecting said shell to said lock barrel; means at the other of the ends of said shell for connecting said shell to said roll-back; a radially inwardly extending shoulder at said other end of said shell; a bar rotatably seated in said shell and normally bearing against said shoulder; means for rotating said bar and for urging said bar longitudinally of said shell; the walls of said shell defining an L-shaped opening having one leg arranged longitudinally of said shell and the other leg circumferentially of said shell; said other leg spaced from said shoulder; a barrier member within said shell and rotatable with respect to said bar; said barrier member having a wing adapted to pass through said L-shaped opening and said slot in said 

